The present technology relates to a solid state imaging device and an electronic apparatus, particularly to a solid state imaging device and an electronic apparatus that can realize a configuration in which an area of a photodiode can be expanded and which can be used in any of a front-surface irradiation type and a back-surface irradiation type.
In a complementary metal oxide semiconductor (CMOS) image sensor, in addition to a photodiode and a floating diffusion region (FD), a plurality of pixel transistors (so-called MOS transistors) are formed in a pixel unit. The plurality of pixel transistors include, for example, a transfer transistor that transfers accumulated charge of the photodiode to the FD, a selection transistor that controls a selection state of the pixels, a reset transistor that resets the charge, an amplification transistor, and the like.
In addition, in recent years, with the advance in miniaturization of the pixels, a shared pixel structure in which a part of pixel transistors is shared by a plurality of pixels is also proposed (for example, refer to Japanese Unexamined Patent Application Publication Nos. 2012-23389 and 2010-141638). In the shared pixel structure, for example, by the FD, the selection transistor, the reset transistor, and the amplification transistor being shared in a plurality of pixels, an area of the pixel transistors arranged in each pixel can be decreased and it is possible to ensure the maximum area of the photodiode which has an effect on the imaging characteristics such as a saturation charge amount and a sensitivity.
Furthermore, a technology to realize a wide dynamic range by increasing a junction capacitance per unit area using the miniaturization of the pixel to improve the saturation charge amount and sequentially read out, is proposed (for example, refer to Japanese Unexamined Patent Application Publication No. 2012-104979).
In addition, in the back-surface irradiation type CMOS image sensor, a technology to further maximize the area of the photodiode by intensively arranging the pixel transistors shared in the plurality of pixels only on B pixels that receive blue light having less transmission light is proposed (for example, refer to Japanese Unexamined Patent Application Publication No. 2008-172580).